Tandem Repeats in 44 Prokaryotic Genomes and Genome Evolution

Genomes are full of various types of repetitive sequences, such as microsatelite, minisatelite, interspersed repeats, tandem repeats, and so on. These repetitive sequences are replete with information that would bring about a better understanding of not only genome evolution but also gene evolution. A tandem repeat (TR) is a DNA sequence piece containing two or more consecutive homologous elements that were arisen as a result of tandem duplication. It is of particular interest and importance with its relation to the gene arrangement or evolution. A TR found across a few coding regions or within a coding region should contain some traces of the gene rearrangement such as gene duplication, gene recombination, or internal gene duplication, which are considered to be the principle mechanisms of protein repertoire expansion[1, 2, 3]. In this study, we tried to investigate genome evolutions by analyzing equivalent TR-pairs detected in 44 prokaryotic genomes.